Lock nut with thread gripping fins



March 8, 1960 H. P. RANDALL LOCK NUT wrm THREAD GRIPPING FINS Original Filed Nov. 20, 1952 INVENTOR.

H. P465 BQNDQLL United States Patent LOCK NUT WITH THREAD GRIPPING FINS Original No. 2,758,627, dated August 14, 1956, Serial No. 321,541, November 20, 1952. Application for reissue April 1, 1957, Serial No. 650,058

11 Claims. (Cl. 151-21) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention relates to a type of check-nut which is used largely in airplane fabrication and construction. They must be light in weight and constructed of highgrade material in order to give them requisite strength in shear along the bolt.

One of the objects of the invention is to produce a nut having qualities of a check-nut, of light weight, and at the same time having ample resistance to shear along the thread of its bolt.

In order to increase the efiiciency of the nut as a checknut, and enable it to resist rotation in a reverse direction after the nut has been screwed up tight upon its seat, the end-portion of the nut remote from the seat is provided with a plurality of inclined fins or tongues that engage the threads of the bolt; and one of the objects of the invent is to provide a construction for the body of the nut and its base portion that will co-operate to develop longitudinal stresses in the fins or tongues when the nut is tightened up, at the same time maintaining a firm support for the roots of the fins or tongues, that will prevent their yielding outwardly when this stress is developed.

Another object of this invention is to provide a nut of shell type having a base portion capable of developing thrust forces in the side walls of the nut, which in turn are imparted to the inclined fins or tongues to increase the force with which their tips engage the bolt thread; and to provide such a nut with means for giving the nut the shear strength developed by the use of the sleeve referred to above, so that in one embodiment of the invention the threaded sleeve can be dispensed with, and the thread shearing strength furnished by an insert or filler carried in the chamber within the nut.

Another object of the invention is to produce a nutblank having a form specially adapting it to be readily threaded to produce a nut having the characteristics described above.

Another object of the invention is to provide a sheetform blank which can readily be transformed by dies toproduce the nut blank referred to above.

Further objects of the invention will be evident from V a careful reading of the specification and a study of the accompanying drawing.

In the drawing: Figure 1 is a plan of a hexagonal nut embodying my invention. A portion of the nut is broken away to show.

, line 33 of Figure 1, but illustrating a different embodiment of the invention, in which the threaded sleeve referred to above is omitted, and an insert substituted pear.

.2 that carries thread to give the necessary strength along its thread.

Figure 4 is a plan of the insert carried by the nut illustrated in Figure 3.

Figure 5 is a plan of the blank of sheet material having features of form that adapt it to be readily transformed by forming dies into the nut-blank shown in Figure 6.

Figure 6 is a longitudinal section through a nut-blank and indicating how it is threaded by a tap.

Referring particularly to the parts, and especially to the embodiment illustrated in Figure 2, the nut has a body 1 of polygonal form, for example, a hexagon, such as illustrated in plan in Figure 1.

In accordance with my invention the peripheral wall of the nut has a series of side walls with dihedral angles at their adjacent edges; and the material composing the side edges of each side wall is integrally united across each dihedral angle to the material in the edge of its adjacent side.

A nut having these characteristics can be formed in different ways. It is preferably made by drawing the body of the nut from a single blank of sheet material by subjecting it to a series of operations by means of dies and forming tools.

The series of walls 2, or fiat faces, of this nut at the corners 3 are integral with each other (see Figure 1), this forms a continuous unbroken hexagonal peripheral wall, and this braces all of the Walls and gives them considerable rigidity for a purpose that will presently ap- These fiat faces form a hexagon, and the faces can be grasped by a wrench.

A plurality of fins 4 are integral with the upper edge of the peripheral wall. These fins, one of which is attached to the edge of each fiat face of the wall, are inclined away from the disc portion and inwardly toward a bolt, such as bolt 7, to which bolt the nut is to be applied. The tips of the fins form an opening therebetween of a diameter less than the diameter of the bolt so as to engage the thread 6 of the bolt 7 to which the nut is applied. Although the edgesS of the tips 5 are of arcuate form, as indicated in Figure 1, and are preferably threaded at the same pitch and number of threads per inch as the bolt, the shear strength of a nut of this type is developed by a sleeve 9 which is integral with the disc-form base portion or base 10 of the nut. The continuous unbroken hexagonal peripheral wall comprising the walls 2 is connected to and integral with and surrounds the disc portion, or base portion 10 of the nut body.

The bore of the sleeve 9 is threaded, of course, with the same pitch and number of threads per inch as the bolt to which the nut is to be applied.

In order to develop the characteristics of a check-nut the base portion 10 of the nut is of dished form, that is, it is of concavo-convex form with its concave side or face disposed downward. The concavo-convex nature of the central disc portions 10 and 13 will be appreciated from an examination of Figs. 2 and 3, respectively. The disc portion has a concave-convex cross-section with respect to a radial plane which passes through the axis of the nut, for example, the radial. plane indicated by line 22 of Fig. 1. It will be readily recognized that this dished form is one which makes the circular zone 12 (herein called contact section 12) the lower-most part of the nut so that the base portion is relieved at the center, and the sleeve at the center of its lower end is axially spaced from and above the contact section 12. Preferably the whole sleeve is axially spaced from and above the contact section 12 as shown in the figures. The result of this is that when the nut is tightened up against a surface 11 that operates as a seat for the nut, considerable pressure is in "aeircularmums where the contacts the seat surface or seat 11. I Furthermore, as the nut" is tightened up, the sleeve 9 ih'c ivs relatively db'wnward'iivith respect to mazes; 115:1: the margin of the base and this, of course, develops "upward stresses'in 'all oftlie "sidewalls '2 of the nut body.

The result of this upward stress in the walls? is to develop-increased thrust forcesi'n the'fins 4. Specifially, this is because the walls 2 at their upper edgesniove rela- '-"*tively up with respect to threaded sleetieand none'of the walls can move outwardly because they are all boundto ea ':l1 other at their edgesor corners 3. I

The threads cut into the bored-f the'sleeve- 9 havejconfsiderahle she'arfstrength, due to the finegi'ade 'of sheet material. This strength will be ample withbutneessitating great length in the sleeve.

However, if the situation inwhich thenutis' to be used ""n'ecessitates increasing the shear-"strength of the" nut adjacent the threads of'the bolt, then the featuresof construcon illustrated in Figure 3 can be' adopted in accordance 'iih rny invention. 'In'this embodimentthe sleeve 9 is dinitted and the base 13 ofthenut-body is provided with anopening 14 which need not be threaded and is jsufiibientl'y large in diameter to slide freely over the bolt ithout rotation. The base'portion 13 has substantially e' samefdish form as-the baseportion 10"shown 'in Figure 2.

The interior of the nut body 15 in this case is provided -%with a filler or insert'16 having a threaded bore 17 to fit rests on the crownof the base 13 the upper face 19 at the insert located substantiallyat the level of the roots "walls.

The insert nut or part 16, of course, is made seats to '20of thefins at their [function] "junction with the'side eenferm to theinterior horizontal"cross-section of the nt'body. In this case also, when thenut is tightenedjup gain'st the surface21; operating as asat for the nut, the eaction" otthe seat 21 will occur in the'circular'zo ne as 'iridicated at the point22, where the base portion joins the sidewalls. This develops an upward thrust indicated "hy' the arrows 23, and this in turn'develops an upward thrust in the side wallsof the nut body as indicated by 'the arrows 24.

thrust force in the fins,'o f course, greatly inc 7 h ses e resistance thatwill be developed by the tint against it any force tending to rotate it in areversedi'rectidn, that "is; in a direction to' loosen the nut.

t Sofa out having these characteristics will not become loose by vibration.

It will be evident that the nut-body 1 shown in Figure '2"and the nut-body'shown in Figure 3 are 'substatitially identical in form except that in the form shown in' Figure the sleeve 9 of'Fi gu're 2 is omitted In completing the'nut shown in Figure 3, itfismecessary to put the insert 16in place'before thefins 25" are b ehtr over to their inclined positions in which'they are "shown in Figure 3. The insert 16, of course; would be "in the'form of a blank'when inserted in the shell of the "nut, and after bending the fins 25 over to their proper inclination, a tap would be run through the insert, and

space between the tips of the fins to cut the thread for the bolt 18. Tapping in thisway would form threads in the same phase in the insertand in the tips'of the fins,

insuring that the finswou'ld run properly in the thread of the bolt when the nut is applied to it.

In both illustrated embodiments of the invention, the .nut is shown having an even number of sides. This is ,.desirable because the forces exerted by the fins are diaqmetrically opposite from each other. v anced forces will also be. obtainedby symmetricallyvdisf "osed sides.v Forexample, the drawings'show a'regu- However, balalzpolygon with equal sides and equal-{dihedralangles.

Q3 t l r p y n ing fe -1n r more a d s (wher y 41 fin a e m t ic y.s aes lirrqyi e tqre rye tors which cancel each other out so that t fi? i .10 u balaccount of the nut.

In Figure 6 I illustrate a nut-blank 26 such as would be employed for making the nut illustrated in Figure 2. In that case also a tap' 'suchhs indicated by the dotted lines 27 would-,be runthrough'the opening in the sleeve 28 of the nut blank, and after cutting the thread there, would have 'intocontact with th egtips of the fins "29 and cut thethreadin them. [In Figure 6 the radius R is indicatedbn'which the concave faceof this blank is struck. The arcuate line struck by the radius preferably -reahestangncy xwith the fillet'or' fillis-t'er 30, the other side ofwhich is tangent to the 'otherface '31 of, the

side walls of the nut-body at'abouftheir"iniddlepoint, although this detail is r elatively unimportant so long as [a pronounced] the dish'or depression that occurs on the face "of the nut'that 'seatsa'ga'inst the surface 21 or 11: ispwno'i e'e d, so""tis,-, tojpiovidei a substantial 'l'ejf. That is to ady, the "base 'p0rt'i6n"10 h'ztsja relieved section at the central part of its lower surfdce krdidcnf'the sleeve The base portion has its contact section at the lnu'inerlal lZ injlFig. 2. T he'rlieved sectioltspaces the ,brise' ofjthe'sleeve" axially from the contact section, Jr

will be noted that the threads in. the sleeve are thereby ele'i 'dted aboi e the contact section. v The nut-blank showu in-Figure 6is, preferably. formed up. fro'mfa plate'rform blankt 32 having the features of construction illustrated in FigurefS. Thisblank, when "'employedto form the nut-blank that hasthe sleeve -9, has a relatively, small, central opening 33-the material immediatelysurrounding which is formed by the dies into the extrusion or sleeve 9 When the plate blaiilgjl is employed tofprodu'ce the nut-blank from whichthe .nut illustrated in;Figure,-3. is made, thegblank 32*will ,have a relatively larger. opening at its center such as indicated bywthe dotted circlef34. v

The material of this blanlg .32may1be considered as composedof 1 a hexagonal; central portion having the J erim etenS S ,indicatedby a: dotted linein Figurelj-S. The six sides of this perimeterlmay be considered 735 composed of rectangular areas-bounded on three sides .by; (a) the boundary-lines 36 that are parallel with the sides-of the hexagon center, and; (b) the end lines for these rectangles indicated-by the dottedlines 37. These rectangles;of course, become bent upon the side 'liIlES'Of the ffhex center tortorm the side walls 2 of -the'r'iut.

.. Beyond-thebouhdarylines 36,-outwardly;projecting tongues 38 arelocated,rhaving converging side edges '39 so that these, tongues have considerable taper. v of these tongueshave concave edges 40 formed v with the The tips concave; side outermost/These arcs 40 wouldbe-at a :pl'etelhe blank; that is they complete 'its outline.

radius that facilitates cutting the threads 'atthetiiis,

.that is tozsay,,they cause'the tongues at their tips to conform substantially tothe'arcofi curvature of the side I of the -bolt,:=and leave sufiicient material to 'cut the full depth of thread with the tap.

:Between the points 41, 41- on the blank, at the roots present and between thesepoints boundary lines 42 coma "this waysmalltriangulanareasare formed between the lines 42 and the end lines 37 of the rectangles that form the side walls of the nut-bodies. This mater-"dial in the tria1igular*'areas-43 is worked by the dies into the end portions of the walls of menu; blanks and resultin a slight increase in the thickness of-material at.the juncwtionr points 3 where the" ends ofthe' sidewalls 20f the nut-are integrally united. distinguishing feature of the fiut descr'ibed ahdve is that the fins 4 are spaced from each other sothat -"the thmstf'rce imparted atjtheir outeriends to the side' walls thatzda'rry: .themis; balanced. 'I-hatI-is tosay; the? 5m- ,jacti ve -thrust forces developed atythe roots'of thei fins thereaction of; the bolt..against' theirtipsado 'not tend to. dis t e p lygonal solid peripheral wall of the nut from its proper form. In other words, due to the action of these forces there is no more tendency to stretch the periphery in any one direction more than in any other direction. This is not true in a nut that employs only two diametrically opposite fins because the forces in them are directed along the same line, and there is no force acting outwardly on the two intermediate inclined side walls to hold them in place.

In the nut described herein, the outward thrust forces in all the fins co-operate to maintain all the dihedral angles between the walls at 120 degrees. And hence every side wall is braced against moving outwardly by the two inclined walls between which it is located.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

I claim as my invention and desire to secure by Letters Patent:

1. A hexagonal nut comprising a central disc portion of concavo-convex cross section with respect to a radial plane passing through the axis of the nut, said nut having a continuous unbroken hexagonal peripheral wall with flat faces forming the hexagon, which wall is connected to and surrounds said disc portion, said disc portion having a central threaded sleeve to receive a bolt extending upwardly therefrom, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the disc portion toward the bolt for engagement therewith, each of the flat faces of the wall constituting the hexagon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter smaller than the diameter of the bolt, and the disc portion having its concave side facing toward the lower edge of said peripheral wall.

2. A polygonal nut comprising a central disc portion of concavo-oonvex cross-section with respect to a radial plane passing through the axis of the nut, said nut having a continuous unbroken peripheral wall with flat faces forming an even-number sided polygon having at least four sides, which wall is connected to and surrounds said disc portion, said disc portion having a central threaded sleeve to receive a bolt extending upwardly therefrom, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the disc portion toward the bolt for engagement therewith,

each of the flat faces of the wall constituting the polygon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter smaller than the diameter 'of the bolt, and the disc portion having its concave side facing toward the lower edge of said peripheral wall.

3. A polygonal nut comprising a central disc portion of cncavo-convex cross-section with respect to a radial I plane passing through the axis of the nut, said nut having a continuous unbroken regular polygonal peripheral wall with at least four sides with fiat faces forming the regular polygon which wall is connected to and surrounds said disc portion, said disc portion having a central threaded sleeve to receive a bolt extending upwardly therefrom, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the disc portion toward the bolt for engagement therewith, each of the fiat faces of the wall constituting the regular polygon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter smaller than the diameter of the bolt, and the disc portion having its concave side facing toward the lower edge of said peripheral wall.

4. A polygonal nut for engagement to a threaded bolt, said nut having a longitudinal axis, and comprising a base portion transverse to and having a hole therethrough on said axis, a contact section and a relieved section on the said base portion, a sleeve having an internally threaded axial hole ther'ethrough integral with said base portion at the hole thereof, said sleeve being adapted to Ihreadedly engage said bolt, the contact secrion and the end of the sleeve adjacent the base portion being axially spaced from each other and on axially opposite sides of the said relieved section whereby the contact section is the bottom-most part of the nut, a coniinuous unbroken regular polygonal wall with at least four sides with flat fac'es forming the regular polygon, which wall is connected to and surrounds said base portion, the upper edge of the peripheral wall having a pluralily of fins integral therewith and inclined away from the base portion and toward the said axis, each of the flat faces of the wall constituting the regular polygon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter no larger than the diameter of the bolt, said opening being axially spaced from the sleeve.

5. A hexagonal nut comprising a central base portion having a contact section which is the bottom-most part of the nut, a continuous unbroken hexagonal peripheral wall with flat faces forming the hexagon, which wall is connected to and surrounds said central base portion, said central base portion having a central threaded sleeve to threadedly engage a bolt extending upwardly therefrom, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the central base toward the bolt for engagement therewith, each of the flat faces of the wall constituting the hexagon carrying one of said fins, said central base portion having its bottom relieved adjacent the central sleeve, whereby the bottom of the sleeve is axially spaced from the bottom of the nut, the free ends of said fins forming an opening therebetween of a diameter no greater than the diameter of the bolt, said opening being axially spaced from the sle'eve.

6. A polygonal nut for engagement to a threaded bolt, said nut having a longitudinal axis, and comprising a base portion transverse to and having a hole therethrough on said axis, a contact section and a relieved section on the said base portion, a sleeve having an internally threaded axial hole therethrough integral with said base portion at the hole thereof, said sleeve being adapted to threadedly engage said bolt, the contact section being the bottom-most part of the nut, a continuous unbroken regular polygonal wall with at least four sides with flat faces forming the regular polygon, which wall is con nected to and surrounds said base portion, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the base portion and toward the said axis, each of the flat faces of the wall constituting the regular polygon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter no larger than the diameter of the bolt, said opening being axially spaced from the sleeve.

7. A nut according to claim 6 in which the said wall is a regular hexagon.

8. A nut according to claim 6 in which the threads in the sleeve are all axially spaced from the contact section.

9. A hexagonal nut comprising a central disc portion of concavo-convex cross section with respect to a radial plane passing through the axis of the nut, said nuthaving a continuous unbroken hexagonal peripheral wall with flat faces forming the hexagon, which wall is connected to and surrounds said disc portion, said disc portion having a central threaded sleeve to receive a bolt extending upwardly therefrom, the upper edge of the peripheral wall having a plurality of fins integral therewith and inclined away from the disc portion and toward the bolt for engagement therewith, each of the flat faces of the wall constituting the hexagon carrying one of said fins, the free ends of said fins forming an opening therebetween of a diameter no larger than the diameter of the bolt, said opening being axially spaced from the sleeve, and the disc portion having its concave side facing towarding the lower edge of said peripheral wall.

- Nov. 13,, 19 16 Ian. 17', ;1 5 0 Iinperman "Pavlinet'z FbifiilGN PATENTS r 1, M h fl,--e----'---'--a---- -T disc portion, said diSc portion hai ing a 'c rial flved ed 67,108 Ne'flierlzin'ds Jim. 15. I951 

